<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			select{width: 120px;height: 24px;}
		</style>
	</head>
	<body>
		<div style="margin: 100px auto;width: 50%;">
			<select id="change_privice"></select>
			<select id="change_city"></select>
			<select id="change_area"></select>
		</div>
		
		<script type="text/javascript">
			/*var domPrice = document.getElementById("change_privice");
			var	dataPrice = {"1:北京","2:上海"};
			domPrice.createElement("option");*/
			
			/*isNaN可以用户判断是否是数字或数字类型的字符串*/
			alert(isNaN(14));/*false*/
			alert(isNaN("14 "));/*false*/
			alert(isNaN(" 14 "));/*false*/
			alert(isNaN("14 d"));/*true*/
			alert(isNaN("1d 14 "));/*true*/
		</script>
		
	</body>
</html>
